A Look Inside Soybean Research

By: Professor Dean Malvick

Plant Pathology Professor Dean MalvickSoybean has become a dominant crop across the Minnesota landscape. Along with this dominance has come challenges from disease. My research and extension program addresses several disease problems with the aim of reducing their impact on yield and seed quality through education and research. My research agenda, along with many cooperators, includes a plethora of “who’s who” in the soybean disease world, including brown stem rot, white mold, Cercospora leaf blight, Phytophthora rot, Pythium seedling rot, sudden death syndrome (SDS), and Rhizoctonia root rot. The latter two have recently been receiving much of our attention and time.

Sudden death syndrome caused by a Fusarium species is a relative newcomer in Minnesota, although it has been wreaking havoc in states to our south for decades. We have been working diligently to understand the disease and pathogen and how to manage them. Thus, we have attacked this disease from many angles. One has been to study with collaborators near and far, the relative value of using resistant varieties as well as seed treatment fungicides and biological controls for management. These are both partially effective, hold promise for more gains and optimization in the future, and are the cornerstones of managing this disease. More questions remain however which has led to new projects. Graduate student Alissa Geske joined the project last June to investigate how soil populations of the fungus relate to disease development in the field, and to determine if remote sensing has value for managing SDS. Lastly, we are initiating a new project, with contributions from new graduate student Rebecca Hall, focused on the Fusarium SDS pathogen and the distribution, host range, and traits of this fungus that may enable its spread and establishment in multiple cropping environments.

Sudden Death Syndrome in SoybeansThe fungus Rhizoctonia has a long-standing reputation as a destroyer of many different crops in Minnesota, one of which is soybean. While this project is not as large as the SDS project, it is an important and promising part of our overall research program. Rhizoctonia root rot is a difficult disease to manage, due to limited management tools available. Our approach to research is two-pronged. Seed treatments and resistant varieties seem to hold the most potential. Thus, we have worked to evaluate and optimize seed treatments, finding that both chemical and biological treatment can be effective and both hold potential for more improvement. The host resistance project has been more exploratory, but our results have suggested that there is a genetic background in some soybean lines that leads to reduced susceptibility to Rhizoctonia root rot and improved yields under Rhizoctonia pressure. Graduate student Pratibha Sharma has recently joined the department to work partly on this project and on Ashok Chanda’s sugar beet Rhizoctonia project.

Each of these projects hold great promise for enhancing knowledge of the biology and management of these serious diseases, both in the short and long term. Only teamwork makes this work possible with essential contributions from a network of staff and collaborators inside and outside of Minnesota. The work could not be done without funding from the Minnesota Soybean Research and Promotion Council, North Central Soybean Research Program, the Minnesota Invasive Terrestrial Plants and Pest Center, industry cooperators, and the Minnesota Agricultural Experiment Station.